When hay is harvested, the standing crop material is cut and deposited on the stubble on the ground in a windrow or swath. Drying is required to lower the moisture content of the crop material to a point where the hay may be picked up and baled or otherwise removed from the field for storage.
When the cut crop is laying in the field, the upper portion of the crop being exposed to the sun and air dries before the bottom portion adjacent the ground. If the farmer waits until the bottom is suitably dry, the upper portion of the crop may be too dry or damaged by rain, in which case leaves may be lost in subsequent harvesting. The leaves contain much of the food value of the hay and need to be preserved. If the leaves become too dry, some will drop off during harvest.
To facilitate drying, hay conditioners have been provided to crush or crack the stems of the crop after the crop is mowed. This may be done with separate machines or combination mower conditioners. Depending on the crop and geography, the crop may be windrowed after cutting and conditioning or the crop may be placed in a swath. This is sometimes dictated by the weather forecast.
When circumstances arise where the crop may become too dry on top and too damp on the bottom, such as occurs if the crop is rained on after cutting, it is desirable to turn over the crop so that the damp side is up and the dry side is down. Also, it is desirable to shift the crop from a damp location in one windrow to dry ground in an adjacent location.
For turning over crop material, whether the crop is in a windrow or swath, rakes, tedders and the like have been provided. Also, crop inverter machines have been developed to turn a crop over to facilitate drying and provide a crop uniformly dry for harvesting.
An inverter machine needs to be so operative that it handles the crop gently and does not knock off leaves in the inverting process. Further, the inverted crop needs to be deposited back on the ground in a uniform, fluffy manner to provide for faster drying. Also, the crop needs to be deposited back on the ground in a manner conducive to subsequent harvesting operations.